Rainer Schultze-Kraft

A comprehensive review, based on about 180 references, synthesizing research and development about Stylosanthes guianensis accession CIAT 184 is presented. This genotype has been widely tested across the tropics and was developed into commercial cultivars in several countries. Agronomic evaluations in a range of disciplines and other research in numerous countries of tropical America, Africa, Southeast Asia and China, and utilization of the legume by farmers are reported. CIAT 184 is particularly successful in southern China, where it gave origin to 5 cultivars. Its outstanding feature is an apparently durable tolerance of the fungal disease, anthracnose (Colletotrichum gloeosporioides), throughout the tropics, with exception of the savanna ecozone in tropical America. Further assets include adaptation to acid, infertile soils, drought tolerance and high production of nutritious dry matter that can be used as traditional forage for ruminants and as leaf meal or pellets to feed monogastrics. CIAT 184 has also found application for soil conservation and improvement (such as erosion control, mulch and green manure), alone or in association with crops and trees. Published work dealing with basic research, mainly conducted in China, is presented. The review concludes with a brief discussion on the current adoption of CIAT 184 and with suggestions regarding future perspectives and research needs.

Crop growth and yield often face sophisticated environmental stresses, especially the low availability of mineral nutrients in soils, such as deficiencies of nitrogen, phosphorus, potassium, and others. Thus, it is of great importance to understand the mechanisms of crop response to mineral nutrient deficiencies, as a basis to contribute to genetic improvement and breeding of crop varieties with high nutrient efficiency for sustainable agriculture. With the advent of large-scale omics approaches, the metabolome based on mass spectrometry has been employed as a powerful and useful technique to dissect the biochemical, molecular, and genetic bases of metabolisms in many crops. Numerous metabolites have been demonstrated to play essential roles in plant growth and cellular stress response to nutrient limitations. Therefore, the purpose of this review was to summarize the recent advances in the dissection of crop metabolism responses to deficiencies of mineral nutrients, as well as the underlying adaptive mechanisms. This review is intended to provide insights into and perspectives on developing crop varieties with high nutrient efficiency through metabolite-based crop improvement.

Stylosanthes macrocephala was described as a new species in 1977 and has become an economically important pasture legume. It has recently been claimed to be conspecific with S. capitata, also an economically important species. This paper refutes this synonymization and summarizes morphological descriptions as well as genetic studies and cytological evidence indicating that diploid S. macrocephala should be considered a separate species, even being a likely progenitor of tetraploid S. capitata. Early confusion with S. bracteata is also discussed.